6 - phosphonomethyl - 2 - (2 - (5 - nitro-2-furyl)vinyl)pyridines and their alkali metal salts,and production thereof



US. Cl. 260240 Claims ABSTRACT OF THE DISCLOSURE 6 phosphonomethyl-2- [2-(5-nitro-2-furyl)vinyl]pyridine and its N-oxide of the formula:

wherein X is N or N O, and their alkali metal salts, which have high antimicrobial activity and are soluble in water with facility. The water solubilities of 6-phosphonomethyl-Z- [2- 5-nitro-2-furyl)vinyl] pyridine monosodium salt and of 6-phosphonomethyl-2-[2-(5-nitro-2- furyl)vinyl] pyridine N-oxide monosodium salt are about 1000 times those of the corresponding 6-hydroxymethy1 compounds.

The present invention relates to 6-phosphonomethyl-2- [2-(5-nitro-2-furyl)vinyl]pyridines (hereinafter referred to as phosphorylated nitrofuran derivative(s)) and their alkali metal salts, and production thereof.

The said phosphorylated nitrofuran derivatives include specifically 6 phosphonomethyl 2-[2-(5-nitro-2-furyl) vinyl] pyridine and its N-oxide and are representable by the following formula:

OzNl J OH=CH wherein X is N or N O.

Hitherto, there have been known a number of nitrofuran derivatives possessing appreciable antimicrobial acnited States Patent 0 tivity. Those are, however, generally soluble in water with much ditficulty, and their practical utilization is obliged to be considerably restricted. 6-hydroxymethyl-2- [2-(S-nitro-Z-furyDvinyl] pyridine and its N-oxide (hereinafter referred to as unphosphorylated nitrofuran derivative(s)) represented by the following formula:

owl J QH OH i onion wherein X is as defined above [1. Pharm. Soc. Japan (Yakugaku Zasshi), 86, 1014 (1966)] exhibit noticeable antimicrobial activity but are not exceptional in the difficult solubility in water.

It has now been discovered that the phosphorylated nitrofuran derivatives (I) and their alkali metal salts, prepared from the unphosphorylated nitrofuran derivatives (II), are highly soluble in water without losing the excellent antimicrobial potency of the original compounds. The present invention is based on this discovery.

Accordingly, a basic object of the present invention is to embody the phosphorylated nitrofuran derivatives (I) and their alkali metal salts. Another object of this invention is to embody the highly water-soluble phosphorylated nitrofuran derivatives (1) and their alkali metal salts possessing excellent antimicrobial activity. A further object of the invention is to embody a process for preparing the phosphorylated nitrofuran derivatives (I) and their alkali metal salts. These and other objects will be apparent to those conversant with the art to which the present invention pertains from the subsequent descriptions.

In accordance with the present invention, the phosphorylated nitrofuran derivative (1) is prepared by reacting the unphosphorylated nitrofuran derivative (II) with a phosphorylating agent in the presence or absence of a solvent. Examples of the phosphorylating agent are phosphoric anhydride, phosphorus oxychloride, phosphorus trichloride, m0rpholinophosphodichloridate and P -diphenyl-P -morpholinopyrophosphorus chloridate. As the solvent, there may be used a non-polar solvent such as benzene or ether. The reaction can proceed at a room temperature but is preferred to efl'ect at a temperature around 50 C.

The resulting phosphorylated nitrofuran derivative (1) is optionally converted into its alkali metal salt by treatment with an aqueous solution of an alkali metal hydroxide (e.g. sodium hydroxide, potassium hydroxide, etc.), an alkali metal carbonate (e.g. sodium carbonate, potassium carbonate, etc.) or the like.

The antimicrobial activity (e.g. antibacterial activity, antifungal activity, antiprotozoal activity) of the thus obtained phosphorylated nitrofuran derivatives (I) and their alkali metal salts is relatively low in vitro but considerably high in vivo. Further, the toxicity of them is so weak as can be practically used. For instance, 6-phosphonomethyl- 2-[2-(5-nitro-2-furyl)vinyl] pyridine N-oxide monosodium salt exhibits the same level potency as o-hydroxymethyl- 2-[2-(5-nitro-2-furyl)vinyl]pyridine N-oxide and chloroxide (3.9 g.) is added, and the resultant mixture is amphenicol in the test on the therapeutic effect against stirred at 50 to 55 C. for 6 hours. The reaction mixture Salmonella typhimurium or Staphylococcus aureus infecis poured into water (130 ml.) and heated on a water tion in mice with the similar level toxicity to the latter bath for 40 minutes. After cooling, the precipitate is colcompounds, as shown in the following table: lected by filtration and recrystallized from water to give k TABLE ED50 (mg/kg.)

Salmonella Staphylococcus Administration lyphimmium aaraus LDsn lest compound route infection 1 infection 2 (mg/kg.) 3

Intravenous. 4. 1 6-phosphonomethyl-2-[%(5-nitro-2-luryl) IntraperitoneaL. 1. 5 vinyl]pyridine N -oxide monosodium salt. Subcutaneous" 4. 7 Oral 12.5 Intravenous 6-hydroxymethyl-2-[2-(5-nitro-2-furyl) IntraperitoneaL. 1. 6 viny1]pyridine N-oxide Subcutaneous Oral 8.8 lntravenpus .1. 2 Chlommphenicol 1211 Oral 13.6

1 Administered once a day for 2 consecutive days. 2 Administered once a day for 8 consecutive days. 3 Acute toxicity in mice.

Compared with the corresponding unphosphorylated 6-ph0sphonomethyl-2[2-(5-nitro-2-fury1vinyl]pyridineN- nitrofuran derivatives (II), the phosphorylated nitrofuran oxide (4.7 g.) as yellow needles melting at 242 C. (dederivatives (I) and their alkali metal salts are dissolved 25 composed).

Well in water. Particularly, the alkali metal salts show The y w needles g-) r i ved in 10% sodimarkedly improved water solubility. For instance, th urn carbonate solution, admixed with active carbon (100 water solubilities of 6-phosphonomethyl-2-[2-(5-nitro 2- mg.) and filtered. The filtrate is made acidic with acetic f 1) i 1]-p idin monosodium l d f 6 ,1 acid and concentrated under reduced pressure to about 10 h th 1-2 [2 s-nitfo 2-furyl)vvinyl]pyridine N 30 ml. The precipitate is collected by filtration and recrystalide monosodium salt are about 20 to about 40 mg./ml. liZed from Water give 'P P y at to 0., whereas those of the corresponding 6- 2 Y Y ]Py OX dc monosodium salt hydroxy-methyl compounds are only about 0.030 to 0.035 as crystals not melting at a temperature lower mg./-ml. at the same temperature. than Therefore, the phosphorylated nitrofuran derivatives Whatis Claimed is! (I) and their alkali metal salts are useful as medicaments A Compound of the fol'mlllai for human beings and animals and also as food preservatives. It is particularly advantageous that they can be used not only in solid preparation forms but also in aqueous 0 solutions such as injection. 40 OBNUOH=OH OHgOi -0H Practical and presently-preferred embodiments of the O X/ I present invention are illustratively shown in the following 0 examples. wherein X is N or N- O, or its alkali metal salt.

EXAMPLE 1 2. The compound according to claim 1, wherein said To a mixture of phosphoric anhydride (15 g.) and 85% c?mpound. 6'pho.sphonoi.nethyl 2 [2'(5'n1tr0'2'furyl) phosphoric acid 19.5 g.) stirred at C. for 1 hour, vmyu'pyndmeorlts alkah nletal Salt 6-hydroxymethyl-2-[2-5-nitro-2-furyl)winyl]pyridine (3.7 comlxlund accordm'g to clalm Wherem the g.) is added, and the resultant mixture is stirred at 50 to alkah metal salt 18 the monos9dlum C. for 6 hours. The reaction mixture is poured into 50 The cpmpound accordmg to clalm Wherem sald water (130 ml.) and heated on a water bath for 40 minclnnpound. 6'phosp.honon.lethyl [z'fimltro'z'furyn utes. After cooling, the precipitate is collected by filtravmyu'pyndme alkahmelal Salt tion and recrystallized from Water to give 6-phosphonocompqund according to clalm wherem the methyl-2-[2-(5-nitro-2-furyl)vinyl] pyridine 4.5 g.) as alkah metal salt is the momwdmm saltyellow needles melting at 221 C. (decomposed). 55

The yellow needles (1.0 g.) are dissolved in 10% References Clted sodium carbonate solution, admixed with active carbon UNITED STATES PATENTS (100 mg.) and filtered. The filtrate is made acidic with acetic acid and concentrated under reduced pressure to about g g 260 297 10 ml. The precipitate is collected by filtration and re- 2666061 1/1954 {nan 260*.297 crystallized from water to give 6-phosphonomethyl-2- arms eta 260297 [2-(5-nitro-2-furyl):vinyl]pyridine monosodium salt (0.8 I N ATENTS g.) as crystals melting at 225 to 230 C. (carbomzed). 1,053,730 l/1967 Great Britain.

EXAMPLE 2 JOHN D. RANDOL To a mixture of phosphoric anhydride (15 g.) and PH, Pnmary Exammer phosphoric acid (19.5 g.) stirred at 50 C. for 1 hour, US. Cl. XJR.

6-hydroxymethy1-2-[2-(5-nitro-2-furyl) vinyl] pyridine N- 4242 64 Patent No.

3,530,122 Dated September 22, 1970 and Yoshikuyi Takase the title, cancel "phosphonomethyl", insert -phosphonoxymethylcolumn 1, lines 19, 36, 41 and 47; column 2, line 61; column 3,

lines 28 and 61; and column 4, lines 23 and 31, cancel "phosphonomethyl", insert --phosphonoxymethyl--.

the Table, in the column headed Test Compound", cancel "phosphonomethyl", insert --phosphonoxymethyl-- column 1, line 35; and column 3, line 30, cancel "phonomethyl",

insert --phonoxymethyl-- column 3, line 53, cancel "6-phosphono-", insert --6-phosphonoxy-- claim 2, line 2; and claim 4, line 2, cancel "6-phosphonomethyl", insert --6-phosphonoxymethyl-.

SIGNED AND E'ALEF 

